1. Field of the Invention
The present invention relates to an operation mechanism for an insertion device provided in an operation section and configured to cause a moving section of an insertion section to move and the insertion device.
2. Description of the Related Art
In recent years, insertion devices, for example, endoscopes have been widely used in a medical field and an industrial field.
With the endoscope used in the medical field, by inserting an elongated insertion section into a body cavity, which is a subject, it is possible to observe an organ in the body cavity and perform various kinds of treatment using a treatment instrument inserted into an insert-through channel for the treatment instrument included in the endoscope according to necessity.
With the endoscope used in the industrial field, by inserting an elongated insertion section of the endoscope into an object such as a jet engine or a pipework of a factory, it is possible to perform observation of scratches, corrosion, and the like and inspections of various kinds of treatment and the like of a part to be inspected in the object.
A configuration is well-known in which a moving section, for example, a bending section bendable in a plurality of directions is provided in the insertion section of the endoscope inserted into the subject/object.
The bending section improves progress of the insertion section in a bent section in a conduit and changes an observation direction of an observation optical system provided at a distal end portion located further on a distal end side in an inserting direction (hereinafter simply referred to as distal end side) than the bending section in the insertion section.
Usually, a plurality of bending pieces are coupled along the inserting direction of the insertion section, whereby the bending section provided in the insertion section of the endoscope is configured to be bendable, for example, in upward, downward, left, and right four directions.
Any one of four wires inserted through the insertion section, a distal end in the insertion direction (hereinafter simply referred to as distal end) of which is fixed to the bending piece located on a most distal end side among the bending pieces, is towed by a bending operation device, which is an operation mechanism, provided in the operation section, whereby the bending section is bendable in any one of the upward, downward, left, and right directions.
More specifically, in the bending section, a turning knob for up-down bending operation provided in the operation section is turned, whereby a sprocket for up-down bending, which is a turning body, provided in the operation section is turned via a turning shaft for up-down bending. Thereafter, one of an upper chain part and a lower chain part of a chain member for up-down bending, which is a long member, wound around the sprocket is towed. As a result, one of an upper wire, a proximal end of which in the inserting direction (hereinafter simply referred to as proximal end) is connected to a distal end of the upper chain part via a connection piece and a distal end of which is connected to the bending piece, and a lower wire, a proximal end of which is connected to a distal end of the lower chain part via a connection piece and a distal end of which is connected to the bending piece, is towed, whereby the bending section is bent in the upward direction or the downward direction.
Further, in the bending section, a turning knob for left-right bending operation provided in the operation section is turned, whereby a sprocket for left-right bending, which is a turning body, provided in the operation section is turned via a turning shaft for left-right bending. Thereafter, one of a left chain part and a right chain part of a chain member for left-right bending, which is a long member, wound around the sprocket is towed. As a result, one of a left wire, a proximal end of which is connected to a distal end of the left chain part via a connection piece and a distal end of which is connected to the bending piece, and a right wire, a proximal end of which is connected to a distal end of the right chain part via a connection piece and a distal end of which is connected to the bending piece, is towed, whereby the bending section is bent in the left direction or the right direction.
The turning shaft for left-right bending, to which the sprocket for left-right bending and the turning knob for left-right bending are fixed, is turnably supported by a frame body extending along the inserting direction fixed in the operation section. Note that the turning shaft for up-down bending, to which the turning knob for up-down bending is fixed, covers an outer circumference of the turning shaft for left-right bending.
The frame body is formed in a thin plate shape from a metal member. The frame body functions as a member that performs positioning of various components provided in the operation section and, when a grasping section is fixed to an operation section main body of the operation section, resists a compression force acting on the operation section forward and backward in the inserting direction and functions as a so-called ground plate, on a distal end side of which a proximal end of the insertion section is fixed.
On one surface of the frame body, a guide member cross-shaped in section that separately guides the upper chain part, the lower chain part, the left chain part, and the right chain part forward and backward in the inserting direction not to interfere with one another is also fixed by screws or the like.
Note that, in the guide member, since the guide member is formed in the cross shape in section, four insert-through paths of the respective chain parts are formed. The respective chain sections are inserted through the respective insert-through paths separately from one another, whereby interference among the respective chain parts is prevented by the guide member.
In a state in which the respective chain parts are inserted through the respective insert-through paths, the chain member for up-down bending and the chain member for left-right bending are located to be superimposed along an superimposing direction of the guide member with respect to the frame body.
More specifically, the upper chain part and the left chain part are located to be superimposed and the lower chain part and the right chain part are located to be superimposed. That is, the upper chain part and the lower chain part or the left chain part and the right chain part are in contact with one surface of the frame body.
Since the operation section includes the grasping section grasped by an operator, a reduction in weight of the operation section is desired to make it easy to perform endoscope operation by the operator who grasps the grasping section.
Therefore, Japanese Patent Application Laid-Open Publication No. 11-192199 discloses a configuration in which, a plurality of thinned portions are formed in the metal frame body provided in the operation section, whereby a reduction in weight of the frame body is achieved.
Incidentally, a configuration is also well known in which a plurality of through-holes (hereinafter simply referred to as holes) are formed in the frame body in order to achieve a further reduction in the weight of the operation section.